<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        var name = window.prompt('你叫什么名字！');
        var age = window.prompt('你多大！');
        var age2 = window.prompt('你多大！');

        var ageall=(age+age2).toFixed(2);
        console.log('你好' + name + '你今年' + age + '岁了');
        document.write('你好' + name + '你今年' + age + '岁了');
    </script>
</body>

</html>